1. Field of the Invention
The present invention is related generally to level indicating devices and tools and, more particularly, is directed towards a pendulum-style level indicator which permits precision alignment of metal tools and work pieces.
2. Description of the Prior Art
Several circumstances exist which require precision alignment tools or devices for which I have discovered that presently available level indicators or the like are woefully inadequate. One such set of circumstances occurs, for example, during the alignment of a metal circular saw blade in circular hand saws, radial saws, table saws, and the like. Alignment of such metal cutting blades poses several unique problems. For example, the cutting blade must be aligned while mounted in the power tool, which presents certain safety problems. Also, the alignment should be taken off of the circular blade itself for greatest accuracy. Further, the physical access to such blades is often restricted, such that a fairly small, compact alignment tool is required.
The safety factor requires a tool that would easily disassociate itself from the blade if power were inadvertantly applied to the tool during the alignment procedure. The requirement of permitting easy selection of setting or reference angles dictated utilization of a pendulum-style, rather than a bubble-style, level. However, presently available pendulum-style levels were found to be far too bulky for the purposes contemplated. A pendulum-style level built with a small indicia-bearing dial face would pose further problems in measurement accuracy.
The prior art pendulum-style levels of which I am aware are deficient in one or more respects. As mentioned above, a sufficiently small dial face would result in reduced accuracy readings. Some of the prior art levels require a prior alignment of surfaces as a reference for future alignments, permanent or difficult attachment of the level to the surfaces with which it is to be utilized, or a non-temporary placement along one axis and at one point of alignment. Overall, the prior art devices lack precision as a result of the failure to provide a precision reference, the failure to provide sufficiently large indicia, and the failure to take into account parallax error.
Typical prior art United States Patents in this general area of which I am aware include the following: U.S. Pat. Nos. 679,577; 1,507,334; 2,527,982; 2,535,791; 2,822,623; and 3,591,925. However, none of the foregoing overcome all of the deficiencies generally discussed above with respect to prior art pendulum-style level indicators.
It was therefore quite apparent to me that a great need exists for a versatile, compact, and precision pendulum-style level which offers readability, accuracy, ease of use, and overcomes all of the deficiencies noted above.